The U.S. Botanic Garden, established by Congress in 1820, is a living plant museum located on the National Mall across from the U.S. Capitol. The Conservatory reopened in December 2001 after a four-year renovation, showcasing an impressive state-of-the-art indoor garden with approximately 4,000 seasonal, tropical and subtropical plants. The U.S. Botanic Garden is administered by the Architect of the Capitol and offers special exhibits and educational programs throughout the year.